Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

70-foot-long, 52-ton concrete bridge survives series of simulated earthquakes

17.07.2014

University of Nevada, Reno's new Earthquake Engineering Lab hosts multiple-shake-table experiments

A 70-foot-long, 52-ton concrete bridge survived a series of earthquakes in the first multiple-shake-table experiment in the University of Nevada, Reno's new Earthquake Engineering Lab, the newest addition to the world-renowned earthquake/seismic engineering facility.


A 70-foot-long, 52-ton concrete bridge survived a series of earthquakes in the first multiple-shake-table experiment in the University of Nevada, Reno's new Earthquake Engineering Lab, the newest addition to the world-renowned earthquake and seismic engineering facility.

Credit: University of Nevada, Reno

"It was a complete success. The bridge withstood the design standard very well and today went over and above 2.2 times the design standard," John Stanton, civil and environmental engineering professor and researcher from the University of Washington, said. Stanton collaborated with Foundation Professor David Sanders of the University of Nevada, Reno in the novel experiment.

"The bridge performed very well," Sanders said. "There was a lot of movement, about 12 percent deflection – which is tremendous – and it's still standing. You could hear the rebar inside the columns shearing, like a zipper opening. Just as it would be expected to do."

The set of three columns swayed precariously, the bridge deck twisted and the sound filled the cavernous laboratory as the three 14- by 14-foot, 50-ton-capacity hydraulically driven shake tables moved the massive structure.

"Sure we broke it, but we exposed it to extreme, off-the-scale conditions," Stanton said. "The important thing is it's still standing, with the columns coming to rest right where they started, meaning it could save lives and property. I'm quite happy."

The bridge was designed and the components were pre-cast at the University of Washington in Seattle, and then built atop three 14- by 14-foot, 50-ton-capacity hydraulically driven shake tables in the 24,500 square-foot lab. It was shaken in a series of simulated earthquakes, culminating in the large ground motions similar to those recorded in the deadly and damaging 1995 magnitude 6.9 earthquake in Kobe, Japan.

The rocking, pre-tensioned concrete bridge support system is a new bridge engineering design the team has developed with the aim of saving lives, reducing on-site construction time and minimizing earthquake damage.

"By building the components off-site we can save time with construction on-site, minimizing interruptions in traffic and lowering construction costs," Sanders said. "In this case, the concrete columns and beams were pre-cast and tensioned at the University of Washington. Other components were built here at the University of Nevada, Reno. It took us only a month to build the bridge, in what would otherwise be a lengthy process."

"This can't be done anywhere else in the nation, and perhaps the world," Ian Buckle, director of the lab and professor of civil engineering, said of the test. "Of course we've been doing these types of large-scale structures experiments for years, but it's exciting to have this first test using multiple tables in this building complete. It's good to see the equipment up and running successfully.

When combined with the University's Large-Scale Structures Laboratory, just steps away from the new lab, the facility comprises the biggest, most versatile large-scale structures, earthquake/seismic engineering facility in the United States, according to National Institute of Standards and Technology, and possibly the largest University-based facility of its kind in the world.

A grand opening was held recently for the $19 million lab expansion project, funded with $12.2 million by the U.S. Department of Commerce's National Institute of Standards and Technology, funds from the Department of Energy, as well as University and donor funds. The expansion allows a broader range of experiments and there is additional space to add a fifth large shake table.

"Our facility is unique worldwide and, combined with the excellence of our faculty and students, will allow us to make even greater contributions to the seismic safety of our state, the nation and the world," Manos Maragakis, dean of the College of Engineering, said. "We will test new designs and materials that will improve our homes, hospitals, offices and highway systems. Remarkable research is carried on here. Getting to this point has taken a lot of hard work. It's both a culmination and a beginning, ushering in a new era."

###

The University of Nevada, Reno earthquake simulation facility is managed as a national shared-use NEES equipment site created and funded by the National Science Foundation to provide new earthquake engineering research testing capabilities for large structural systems.

The rocking bridge-bent accelerated bridge construction project is sponsored by the National Science Foundation George Brown Network for Earthquake Engineering Systems Research Program (Award #1207903).

For more technical information about the experiment, see the news release posted at the NEES website: https://nees.org/announcements/new-bridge-design-improves-earthquake-resistance-reduces-damage-and-speeds-construction.

YouTube of bridge shaking: https://www.youtube.com/watch?v=6jkdsIfs6pU

Time-lapse and photo gallery of construction of the new laboratory: http://imedia.unr.edu/ShakerTables/.

Time-lapse video of bridge construction: http://youtu.be/MjDcEA4f40M.

Founded in 1874 as Nevada's land-grant university, the University of Nevada, Reno ranks in the top tier of best national universities. With nearly 19,000 students, the University is driven to contribute a culture of student success, world-improving research and outreach that enhances communities and business. Part of the Nevada System of Higher Education, the University has the system's largest research program and is home to the state's medical school. With outreach and education programs in all Nevada counties and home to one of the largest study-abroad consortiums, the University extends across the state and around the world. For more information, visit http://www.unr.edu.

Mike Wolterbeek | Eurek Alert!

More articles from Architecture and Construction:

nachricht Smarter window materials can control light and energy
23.07.2015 | University of Texas at Austin

nachricht University of Cincinnati, industry partners develop low-cost, 'tunable' window tintings
11.06.2015 | University of Cincinnati

All articles from Architecture and Construction >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: What would a tsunami in the Mediterranean look like?

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).

Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...

Im Focus: Self-healing landscape: landslides after earthquake

In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.

These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...

Im Focus: FIC Proteins Send Bacteria Into Hibernation

Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.

For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...

Im Focus: Fraunhofer IPA develops prototype of intelligent care cart

It comes when called, bringing care utensils with it and recording how they are used: Fraunhofer IPA is developing an intelligent care cart that provides care staff with physical and informational support in their day-to-day work. The scientists at Fraunhofer IPA have now completed a first prototype. In doing so, they are continuing in their efforts to improve working conditions in the care sector and are developing solutions designed to address the challenges of demographic change.

Technical assistance systems can improve the difficult working conditions in residential nursing homes and hospitals by helping the staff in their work and...

Im Focus: A Grand Voyage for Tiny Organisms

Climate and Ecosystem Change in the Mediterranean

Since the opening of the Suez Canal in 1869 many hundreds of marine animal and plant species from the Red Sea have invaded the eastern Mediterranean, leading...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

Large agribusiness management strategies

19.08.2015 | Event News

 
Latest News

Cells cling and spiral 'like vines' in first 3-D tissue scaffold for plants

27.08.2015 | Life Sciences

Hypoallergenic parks: Coming soon?

27.08.2015 | Health and Medicine

Stiffer breast tissue in obese women promotes tumors

27.08.2015 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>